VATICAN CITY, Jan 29 (Reuters) - Pope Francis called on European countries on Monday to do more to fight anti-Semitism, saying indifference on the issue was a virus that could allow the ideas of racial hatred to spread.

Francis issued his appeal in a speech to a Rome conference on the responsibility of states to fight anti-Semitism and crimes associated with it.

“We are responsible when we are able to respond. It is not merely a question of analyzing the causes of violence and refuting their (anti-Semitic crimes’) perverse logic, but of being actively prepared to respond to them,” he told the event organized by the Organisation for Security and Cooperation in Europe (OSCE).

A number of European nations have made it illegal to deny the Holocaust, the Nazi attempt to exterminate European Jewry during World War Two.

Last week, Germany’s lower house of parliament called for the creation of a new government post to oversee the fight against anti-Semitism, following the burning of Jewish symbols and Israeli flags.

“Indifference is a virus that is dangerously contagious in our time, a time when we are ever more connected with others, but are increasingly less attentive to others,” the pope said.

Francis, who made an emotional visit to the former Nazi death camp at Auschwitz in 2016 and visited Rome’s synagogue the same year, said the “vaccine” against “so many deplorable forms of apathy” is memory.

Quoting his predecessor, Pope John Paul, Francis said everyone should work for a future where “the unspeakable iniquity of the Shoah will never again be possible.” Shoah is the Hebrew word for the Holocaust.